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MOve the sync patterm 60 symbols (5.12 s) into the transmission.

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Joe Taylor 2024-01-30 18:34:43 -05:00
parent 27824dc45d
commit aedc9ec3c1
1 changed files with 13 additions and 12 deletions
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25
lib/superfox/synctest.f90
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@ -11,10 +11,10 @@ program synctest
real*4 xnoise(NMAX) !Random noise
real*4 dat(NMAX) !Generated real data
real ccf(-MMAX:MMAX,-JMAX:JMAX) !2D CCF: DT, dFreq offsets
complex cdat(-15000:NMAX) !Generated complex waveform
complex cdat(NMAX) !Generated complex waveform
complex clo(NMAX) !Complex Local Oscillator
complex cnoise(NMAX) !Complex noise
complex crcvd(-15000:NMAX) !Signal as received
complex crcvd(NMAX) !Signal as received
complex c(0:NFFT-1)
complex w,wstep,w0,wstep0
integer ipk(2)
@ -37,18 +37,19 @@ program synctest
call getarg(4,arg)
read(arg,*) snrdb
nsps=1024
ntrperiod=15
rms=100.
fsample=12000.d0 !Sample rate (Hz)
fsample=12000.0 !Sample rate (Hz)
npts=fsample*ntrperiod !Total samples in .wav file
twopi=8.d0*atan(1.d0)
twopi=8.0*atan(1.0)
tsync=2.0
nsync=fsample*tsync
nsym=125 !Number of channel symbols
nsps=1024
nsync=tsync*fsample
baud=12000.d0/nsps !Keying rate (6.67 baud fot 15-s sequences)
baud=12000.0/nsps !Keying rate (6.67 baud fot 15-s sequences)
h=default_header(12000,npts)
fname='000000_000001.wav'
open(10,file=trim(fname),access='stream',status='unknown')
@ -73,11 +74,11 @@ program synctest
a1=f0 + syncwidth/2.0 !Frequency at midpoint of sync waveform
a2=2.0*syncwidth/tsync !Frequency drift rate
! Generate complex sync signal
! Generate complex LO and sync signal
x0=0.5*(nsync+1)
s=2.0/nsync
cdat=0.
i0=xdt*12000.0
i0=nint(60.0*nsps + xdt*12000.0)
do i=1,nsync
if(i.eq.nsync/2+1) a2=-a2 !Reverse sign of drift at midpoint
x=s*(i-x0)
@ -98,14 +99,14 @@ program synctest
write(10) h,iwave(1:npts) !Save the .wav file
close(10)
crcvd(-1000:0)=0.
crcvd=0.
crcvd(1:NMAX)=cdat(1:NMAX) + cnoise
ccf=0.
df=12000.0/NFFT !0.366211
i1=60*nsps
do m=-MMAX,MMAX
lag=100*m
! c(0:nsync-1)=crcvd(1+lag:nsync+lag)*conjg(cdat(1:nsync))
c(0:nsync-1)=crcvd(1+lag:nsync+lag)*clo(1:nsync)
c(0:nsync-1)=crcvd(i1+1+lag:i1+nsync+lag)*clo(1:nsync)
c(nsync:)=0.
fac=1.e-3
c=fac*c
@ -119,6 +120,7 @@ program synctest
ccf=ccf/maxval(ccf)
ipk=maxloc(ccf)
print*,i0,ipk(1)
ipk(1)=ipk(1)-MMAX-1
ipk(2)=ipk(2)-JMAX-1
ma=ipk(1)-10
@ -133,10 +135,9 @@ program synctest
write(*,1300) m/120.0,line
1300 format(f6.3,2x,61a1)
enddo
dt=ipk(1)/120.0
t=ipk(1)/120.0
dfreq=ipk(2)*df
f=1500.0+dfreq
t=dt
write(*,1100) f0,xdt
1100 format(/'f0:',f7.1,' xdt:',f6.2)
write(*,1112) f,t